I'm going by the assumption that you have windows XP as written below your user name. Below is the instructions on how to open disk management, taken from Microsoft website.
How to use Disk Management
To start Disk Management:
Log on as administrator or as a member of the Administrators group.
Click Start, click Run, type compmgmt.msc, and then click OK.
In the console tree, click Disk Management. The Disk Management window appears. Your disks and volumes appear in a graphical view and list view. To customize how you view your disks and volumes in the upper and lower panes of the window, point to Top or Bottom on the View menu, and then click the view that you want to use.